Concrete wall form panel with inherently reinforced crossbars



CONCRETE WALL FORM PANEL WITH INHERENTLY REINFORCED CROSSBARS Filed July28, 1965 e. F. BOWDEN Jan. 9, 1968 2 Sheets-Sheet 1 INVENTOR GEORGE EBOWDEN EM Nm I\NN ATT'Y Jan. 9, 1968 G. F. BOWDEN 3,362,676

CONCRETE WALL FORM PANEL WITH INHERENTLY REINFORCED CROSSBARS Filed July28, 1965 2 Sheets-Sheet 2 7 154 INVENTOR GEORGE F. BOWDEN United StatesPatent Ofiice 3,362,675 Patented .Ian. 9, 1968 3,362,676 CONCRETE WALLFORM PANEL WITH IN- HERENTLY REINFGRCED CROSSBARS.

George F. Bowden, Des Plaines, IlL, assignor to Symons Mfg. Company, DesPlaines, III, a corporation of Delaware Filed July 28, 1965, Ser. No.475,504 3 Claims. (Cl. 249-492) ABSTRACT 6F THE DISCLOSURE Asteel-studded concrete wall form panel reinforced by crossbars which,although they are equally spaced along the length of the panel so thatadjacent crossbars subtend equal included openings therebetween, do notinterfere with the use of conventional fastening bolts which are appliedto the side frame members at equally spaced fixed centers therealong.

The present invention relates to a novel panel for use in conection witha concrete wall form, the panel being similar to that which isillustrated and described in United States Patent No, 3,171,186, grantedon March 2, 1965, and entitled, Wall Form Panel With InherentlyReinforced Crossbars, and having associated therewith novel reinforcingcrossbars by means of which the plywood panel facing is more effectivelybraced against outward bulging than has heretofore been possible.

The present invention, as well as the invention of the aforesaid patent,has particular reference to a prefabricated concrete wall form panel ofthe type which is commonly known as a Steel'Ply panel and ismanufactured and sold by Symons Mfg. Company of Des Plaines, Ill.

In order to accommodate the concrete hardware which is used with panelsof the character under consideration, the longitudinal and transverseframe members of the reinforcing frames of the panels are formed withtransverse slots therein, such slots being set at approximately one-footcenters. Most of the hardware that is employed is designed to cooperateWith these slots, and included in such hardware are conventional T-boltand wedge assemblies which are employed for drawing the adjacent edgesof the edge-to-edge panels together.

In the large-sized panels which constitute as much as 95% of all thepanels which are manufactured and used, it is absolutely essential thatthe medial regions of the plywood facings be reinforced against outwardbulging under the tremendous thrust of the wet poured concrete and,accordingly, the aforementioned reinforcing crossbars are provided, andthey divide the rectangular marginal reinforcing frames into a number ofincluded frame openings which are rectangular and have their longdimension extending transversely of the panels.

In order to maintain a spacing as nearly as possible to twelve inches,the crossbars of each panel are caused to traverse the reinforcing frameslightly above or slightly below the level of the slots. To preserveend-for-end reversibility of each panel, all of the crossbars on oneside of (i.e., above) a medial horizontal plane are positioned justabove the level of the adjacent slots, while the crossbars on the otherside of (i.e., below) such plane are positioned just below the level ofthe adjacent slots. This obviously establishes a medial included openingwhich is of greater height than the other openings. The crossbars of aSteel-Ply concrete wall form panel are ordinarily in the form of anglepieces which are L-shape in transverse cross section, and wheninstalled, one flange of each cross bar extends vertically and lies flatagainst the plywood facing. The direction of extent of the variousvertically disposed crossbar flanges still further modifies the heightof the included openings between crossbars. When the vertically disposedflanges extend in the same direction, the height of the included openingis reduced. When such flanges extend away from each other in oppositedirections, the height of the included opening is increased.

The present invention contemplates the provision of a Steel-Ply typeconcrete Wall form panel having associated therewith crossbars which areso designed that equal crossbar spacing is attained, thus rendering thevarious included openings in the rectangular marginal frame of the panelsubstantially the same in size or area. Still further, by such anarrangement, the effective spacing between each pair of adjacentcrossbars is reduced to such an extent that in-between maximum plywooddeflection is materially reduced.

The provision of a concrete wall form panel such as is briefly outlinedabove and possessing the stated advantages constitutes the principalobject of the present invention. Other objects and advantages, not atthis time enumerated, will readily suggest themselves as the followingdescription ensues.

In the accompanying two sheets of drawings forming a part of thisspecification, one illustrative embodiment of the invention is shown.

In these drawings:

FIG. 1 is a fragmentary perspective View of one side of a concrete wallform, showing two of the Steel-Ply type panels of the present inventionoperatively connected together in edge-to-edge relationship, and alsoshowing a standard or conventional Steel-Ply panel associated with theassembly of the two improved panels;

FIG. 2 is a rear or outside plan view of one of the panels of FIG. 1,the panel being shown without any connecting hardware in associatedrelation with it;

FIG. 3 is an enlarged perspective view of one of the improved crossbarswhich are employed in connection with the invention;

FIG. 4 is an enlarged fragmentary rear or outside perspective view of amedial portion of the concrete wall form panel of FIG. 2, such viewbeing in the vicinity of one of the improved crossbars;

FIG. 5 is a right-hand end view of the crossbar of FIG. 3;

FIG. 6 is a vertical sectional view taken substantially on the line 66of FIG. 3;

FIG. 7 is a left-hand end view of the crossbar of FIG. 3; and

FIG. 8 is a composite view illustrating in detail the manner in whichthe crossbar of FIG. 3 is formed.

Because of the fact that the particular concrete wall form panel of thepresent invention represents an improvement over a specific andrecently-developed form of Steel-Ply panel, and because thelast-mentioned panel is of an intricate nature involving, as it does,specific cross-sectional shapes for the marginal frame members, specificdimensions that cannot be deviated from, specific crossbar spacingwhich, if deviated from, renders the panel unsatisfactory in commercialuse, and specific facilities for the attachment thereto of variousarticles of concrete wall form hardware, it is deemed necessary toillustrate in the accompanying drawings an exemplary Steel-Ply panel asit is currently manufactured and used, and to describe the same indetail to the end that reference may be had thereto for comparisonpurposes when a description is made of the panel of the presentinvention. Such an illustration has been made in FIG. 1.

Referring now to FIG. 1, a conventional Steel-Ply concrete wall formpanel is illustrated in this view and designated in its entirety by thereference numeral 10. The panel 10 is shown as forming a part of oneside of a composite concrete wall form 12 and is illustrated with twoimproved Steel-Ply panels 14, the latter being constructed according tothe present invention and forming other parts of the one side of theform 12. The standard panel and the two improved panels 14 aremaintained in their normal edge-to-edge relationship by means ofconventional T-bolt and wedge assemblies 16 and the side of the wallform 12 that is partly formed by the panels 19 and 14 is maintained inspaced parallel relationship with respect to the other concrete wallform side (not shown) by means of horizontal tie rods 18 having loopedends 19. The T-bolt and wedge assemblies 16 and the tie rods 18 areconventional items of concrete wall form hardware and their nature andfunction will be set forth in greater detail presently when thecharacter of the panels 10 and 14 is better understood.

The conventional or standard panel 1% is of the prefabricated Steel-Plytype, such a panel being of open shallow tray-like design and includinga rectangular plywood facing 20 and a marginal rectangular steelreinforcing frame comprising longitudinal frame members 22 andtransverse frame members 23. The panel 10 is shown as being positionedwith its longitudinal frame members 22 extending vertically and with itstransverse frame members 23 extending horizontally and thus furtherreference to the panel It} may be made on the basis of its position inthe wall form 12. At appropriate levels in the panel 10, intermediatehorizontal steel Crossbars 24 in the form of angle pieces extendbetween, and are welded to, the opposed vertical frame mem bers 22.

The frame members 22 and 23 are in the form of structural steel barswhich are of shallow channel shape in cross section, and each barincludes inside and outside outwardly extending marginal ribs 26 and 28,and a connecting base or web portion 30. On the side of each web portionthat is opposite to the ribs 26 and 28 is a lateral inwardly extendingflange 32 on which the adjacent edge of the plywood facing 20 seats withits inside face flush with the inside edges of the frame members 22 and23.

At vertically spaced regions along the marginal ribs 26 and 28, pairs oftransversely registering notches 34 are formed and these notches, whenthe frame members are in contiguity, define therebetween horizontalchannel voids which are adapted to receive therethrough the adjacentlooped ends 19 of the tie rods 18. A rectangular slot 36 is formed inthe web portion 30 of each frame member at the level of each pair ofnotches 34 and such slot is adapted to receive therethrough the shankportion of the T-bolt of one of the T-bolt and wedge assemblies 16whereby the contiguous or abutting frame members of adjoining panels aredrawn tightly together. The various groups of notches 34 and slots 36 inthe vertical frame members 22 are ordinarily formed on twelve-inchcenters and in such a manner as to insure that when endover-endreversibility of any panel is resorted to, notch alignment betweencontiguous frame members 22 will be preserved.

It will be observed that in connection with the conventional Steel-Plyconcrete wall form panel 10, the various crossbars 24 which, aspreviously stated, are in the form of angle pieces, include verticalflanges 4-0 and horizontal flanges 42. The various horizontal flanges 42are formed with notches 44 in the end regions thereof in order toaccommodate the wedge parts of the T-bolt and wedge assemblies 16. Thus,it is essential that the horizontal flanges 42 of each crossbar 24 beslightly offset from the horizontal plane of the adjacent slots 36 sothat there will be no interference thereof with the T-bolts. Thisvertical offsetting of the crossbars 24 from the horizontal level of theslots 36 and the notches 44 precludes accurate placing of the crossbarson twelve-inch centers to attain the optimum condition of equal-sizedincluded openings in the panel frame. Accordingly, and in order topreserve the possibility of end-to-end reversal of the panel in a givenconcrete wall form installation, the crossbars in the upper region ofthe panel are positioned with their vertical flanges 4t} projectingupwardly, while the crossbars in the lower region of the panel arepositioned with their vertical flanges 4% extending downwardly. In theillustrated form of the panel 10, there are four crossbars and fiveincluded openings in the panel frame. Thus, the two uppermost and thetwo lowermost included openings, labelled a, I), and d, e, respectively,are of equal height, while the medial opening, labelled c, is ofappreciably greater height.

It is pointed out that the plywood facing that is employed in connectionwith a conventional Steel-Ply concrete wall form panel like the panel 10is invariably in the form of a laminated structure of the five-plyvariety with the thickness of the lamination being equal and with theover-all thickness of the facing being one-half inch so that theindividual plies are each one-tenth of an inch thick. As purchased fromthe manufacturer for subsequent fitting operations in connection withthe installation of the plywood facing in the marginal steel reinforcingframe, the grain structures of the various plies run at right anglesalternately in different directions so that the outside or surfaceplies, as well as the center ply, have their grain structure running inthe same direction. Based solely upon numerical superiority, it isobvious that a plywood facing of this character will have greaterstrength against flexing in one direction than it will in the other. Asa matter of fact, when plywood is subjected to bending or flexingstresses across a given span, only those plies which have their grainrunning lengthwise of the span are considered as carrying the load. Thecross plies, being stressed across the grain, are incapable ofcontributing any significant amount of resistance to such flexing orbending. These considerations are not altered appreciably by the factthat a concrete wall form panel facing of plywood is supported along allfour marginal edges since the reinforcement offered at the marginaledges is effective only in the immediate vicinity of the panel members.For these reasons, and in order to attain the greatest resistance toflexing, it is customary to cut and install the plywood facing in therectangular frame of a conventional Steel-Ply panel so that thepredominance of plywood grain structure runs in the direction of theshortest span associated with each included opening in the frame. Thisfact should be borne in mind in connection with the followingconsiderations which are given to the deflection of the plywood facingacross the included openings in the frame of a standard Steel-Ply panelsuch as the panel 10 that is illustrated herein, the deflection arising,of course, under the pressure of wet concrete in any given concrete wallform installation.

It has been found in actual practice that the height of the includedopenings, (1, b, c, d, and e in a conventional Steel-Ply panel is suchthat under a heavy concrete load, the previously-mentioned pillow blockor quilting effect obtains in the completed concrete wall structureafter the panel is removed. Under a more moderate load, this effect maynot be noticeable in connection with the included openings a, b, d ande, but it is likely to be noticeable in connection with the includedmedial opening 0 which has an appreciably greater height than the otheropenings. Theoretical considerations have shown that the maximumdeflection of a beam under load across a given span, i.e., thedeflection at mid-span, may be represented by the equation where Arepresents maximum deflection, K is a constant that varies with the typeof span, W is the weight per unit of length, 1 is the length of thespan, E is the modulus of elasticity of the beam, and I is the moment ofinertia. From this equation, it will be seen that maximum defiectionvaries as a function of the fourth power of the length of the span and,consequently, any reduction in the length of the span, however small,will effect a material reduction in the amount of beam deflection.

According to the present invention, a reduction equal to the full widthof the vertical flange 40 of one of the angle piece type crossbars 24 isaccomplished in the effective height of the included openingscorresponding to the openings b and d, and in the case of the openingwhich corresponds to the included opening 0, an additional reduction iseffected. These reductions amount to approximately one and three-eighthsinches for the smaller openings and approximately three andthree-eighths inches for the large medial opening. Comparative testsshown that maximum deflection has been substantially cut in half.Moreover, the reductions have been accomplished without adding unduly tothe over-all weight of the panel. The reductions are made possible bythe particular design and construction of the crossbars and a noveldisposition of the crossbars within the panel frame, as will now be setforth in detail.

In the panel 14 of the present invention, the plywood facing 120 and themarginal frame members 122 and 123 remain substantially the same as inthe herein illustrated conventional Steel-Ply panel 10 and, therefore,in order to avoid needless repetition of description, similar referencenumerals but of a higher order have been applied to the correspondingparts as between the respective illustrations of the two panels. Thewall form hardware, such as the T-bolt and wedge assemblies 16 and thetie rods 18 which are used in connection with the panel 10, are capableof accommodation by the panel 14 and thus, wherever such hardware isillustrated in connection with either panel, identical referencenumerals have been applied thereto. The only ditference between thepanels 10 and 14 resides in the novel construction and disposition ofthe various crossbars 124 which are associated with the improved panel14.

Each crossbar 124 is in the form of an integral structural member whichis formed from an elongated flat blank B (see FIG. 8) of heavy gaugesheet steel stock, the blank being in the form of a parallelogram whichis of slight angularity and has parallel side edges 11 and 13 andparallel end edges 15 and 17. As shown in FIG. 8, the end edges 15 and17 extend at an extremely small angle with respect to the side edges.The blank B is folded upon itself along a medial fold line 21 whichextends at right angles to the end edges 15 and 17, and it is also bentalong lines 19 which also extend at right angles to these end edges andintersect the obtuse corners of the blank. The net result of thisfolding and bending is the crossbar 124 which is shown at the extremeright-hand side of FIG. 8 and is illustrated in further detail in FIG. 3after certain notching and bending operations have been performed, aswill be described presently.

The completed crossbar 124 thus is comprised of a folded diagonaldual-thickness rib 150 from which there extend laterally in oppositedirections two right triangular flanges 152 and 154. Each flange 152 or154, as the case may be, has its base coextensive with the rib 150 andhas its hypotenuse extending horizontally between the two vertical frameside members 122. The crossbar 124 is, therefore, generally of T-shapein medial transverse cross section as shown in FIG. 6, and it isgenerally L-shaped in transverse cross section at its end regions asshown in FIGS. 5 and 7.

As best seen in FIGS. 3 and 4, the outermost end regions of the flanges152 and 154 are bent at a slight angle so as to form inwardly-offsetparts 156, and notches 158 are cut through the opposite end regions ofthe dual-thickness rib 150 for purposes that will be made clearpresently.

Considering the crossbars 124 in their environment in the panel 14, eachcrossbar has its flange 152 projecting upwardly and its flange 154projecting downwardly with both flanges bearing flatly against the outerface of the plywood panel 120. Each crossbar 124 is centered between anadjacent pair of opposed slots 136 in the vertical frame members 122 sothat the left-hand end region of its dualthickness rib 150 overlies theadjacent slot as viewed in 6 FIGS. 1 and 2, while the right-hand endregion of the rib underlies the adjacent slot 136. The inwardly offsetend parts 156 of the two flanges 152 and 154 afford clearance for theadjacent plywood-receiving flanges 132, while the notches 158 affordclearance for the wedge parts of the T-bolt and wedge assemblies 16.

The crossbars 24 of the present invention in no way interfere with theuse of conventional concrete wall form hardware inasmuch as the variousslots 136 are not obstructed, nor are the entrance openings leadingthereto on either side of the frame members 122. The T-bolts of theassemblies 16 may be passed through the slots 136 from either side ofthe associated longitudinal frame member and the wedges have clearancefor insertion through the T-bolts by reason of the notches 158 in theribs regardless of whether the T -bolt overlies or underlies theadjacent diagonal rib. The use of such hardware is illustrated in FIG. 4wherein the shank part of the T-bolt of one assembly 16 overlies theadjacent diagonal rib at the right-hand side of this view so that thewedge is driven upwardly, while the shank portion of the T-bolt ofanother assembly 16 underlies the adjacent diagonal rib at the left-handside of the view so that the wedge is driven downwardly.

Referring again to FIG. 1 and comparing the panel 10 with either of thepanels 14, it will be observed that the various included openings a, b,c, d and e of the frame of the panel 14 present equal vertical spans,whereas in the frame of the panel 10, the span of the included opening cis appreciably greater than the spans of the openings at, b, d, and e.Moreover, the span of any one of the included openings in the frame ofthe panel 14 is no greater than is the smallest span of any of theincluded openings in the frame of the panel 10. Dimensionalconsiderations are important to the present invention inasmuch as with apanel of any given width, there is an optimum length of span which, ifexceeded, will give rise to pillow block effects on the finishedconcrete wall or other structure.

The invention is not to be limited to the exact arrangement of partsshown in the accompanying drawings or described in this specification asvarious changes in the details of construction may be resorted towithout departing from the spirit or scope of the invention. Forexample, whereas the crossbars 24 of the present invention have beenshown as being formed by a folding and bending operation from a flatblank of heavy gauge sheet steel, it is contemplated that, if desired,these crossbars may be in the form of integral extruded or rolledstructures. Therefore, only insofar as the invention has particularlybeen pointed out in the accompanying claims is the same to be limited.

Having thus described the invention what I claim as new and desire tosecure by Letters Patent is:

1. A concrete wall form panel adapted to be positioned vertically and inedge-to-edge relation with like panels for purposes of forming a part ofa concrete wall form, said panel comprising a rectangular plywood facingand a rectangular marginal reinforcing frame including vertical opposedparallel side members and horizontal opposed parallel end members, saidside members being provided with vertically spaced pairs of opposedbolt-receiving openings at equally spaced horizontal levels, and aseries of transversely extending facing reinforcing crossbars havingtheir ends secured to the side members respectively, there being onecrossbar for each pair of openings, each crossbar presenting a narrow,elongated, flat, substantially rectangular portion which bearscoextensively in face-toface contact against the plywood facing andspans the distance between the opposed vertical side members at thelevel of one opposed pair of bolt-receiving openings, and a medialreinforcing rib extending at a right angle to the plane of said flat,substantially rectangular portion, connected thereto, and extendingdiagonally thereacross so that one end region of the rib underlies oneof said opposed bolt-receiving openings and the other end region of therib overlies the other opposed bolt-receiving opening.

2. A concrete Wall form panel as set forth in claim 1 and wherein saidrib has its mid-point disposed at the horizontal level of the associatedpair of opposed boltreceiving openings.

3. A concrete Wall form panel as set forth in claim 1 and wherein saidrib has its mid-point disposed at the horizontal level of the associatedpair of opposed bolt- References Cited UNITED STATES PATENTS 1/1949 Pirz249192 X 3/1965 Bowden 249191 WILLIAM J STEPHEN, Primary Examiner.

